As Hurricane Maria roared over the island of Dominica on Tuesday, dozens of parents of students at Ross University School of Medicine posted anguished messages on the school’s Facebook page, searching for their children and praying that they had survived unscathed.

As other forms of communication went dark, the Facebook appeals sailed out like messages in a bottle. The school set up a hotline for parents to call, but it was constantly busy.

On Tuesday afternoon, Ross’s dean said university officials were still struggling to determine the whereabouts of many students and faculty, and were reaching out to the United States and Canadian governments for help.

“I’m a concerned parent waiting on information about my son,” one woman, Marina Agadzi, wrote on the Facebook page on Tuesday. “Last I heard from him was 1645 pm yesterday then lost contact.”

Another parent, Yamirka Machin, said she had been praying for all of the medical students and begged, “We are desperate without any news.”

Offshore medical schools have proliferated in recent decades, offering an alternative to highly competitive American schools with limited slots for the many students hungering to be doctors.

For the Caribbean schools’ students, it is often a triumph and a relief to be accepted into any medical school at all — and a welcome bonus if that school happens to be in a tropical paradise. But in this season of one deadly hurricane after another, for some students that paradise has turned into a version of hell.

Maria came days after Hurricane Irma hit St. Martin, causing the military evacuation of hundreds of people from another medical school, the American University of the Caribbean. Both Ross and American are part of Adtalem Global Education, formerly known as DeVry Education Group, a for-profit educational company with headquarters near Chicago.

If the hurricane damage prevents the schools from rebuilding quickly or students from graduating on time, it could be devastating both to the universities and to the financial and career prospects of their students, many of whom have taken out huge loans.

As Irma’s eye passed over St. Martin last week, Chris Glynn, 32, a student at American, said he opened the door to his apartment to find several classmates huddled in the hall. Their balcony doors and roof had been ripped off.

The group waited out the rest of the storm in his back room. Mr. Glynn, who was evacuated by military plane along with his wife and 3-year-old daughter, is now just hoping he will be able to start the semester in time to take the test that will qualify him to be matched for a residency at a United States hospital.

“If not,” he said by phone Tuesday from his in-laws’ home in Pittsburgh, “it would be a lost year.”

There are dozens of medical schools in the Caribbean, and some of the more established ones, like Ross and St. George’s in Grenada, have better reputations than others. Most are for-profit, and they serve their students by pointing them toward high-demand positions like primary care in rural and poor urban areas.

Their tuition is comparable to or even higher than at United States schools, and their students often graduate with more debt than their mainland counterparts. Some Caribbean schools have used their cash to pay United States hospitals to reserve clinical training spots for their students during their third and fourth years of medical school.

They have faced fierce resistance from American medical schools, who have argued that the Caribbean schools provide inferior education, and have also guarded their turf by trying to block students of offshore schools from the clinical rotations they need to graduate.

Dr. William Owen, Ross’s dean and chancellor, said in a statement that the school was providing updates to families as quickly as it could, but was still trying to “confirm the safety of our people, provide supplies and shelter, and ultimately evacuate our community.”

A woman who answered the hurricane hotline for another school in Dominica, All Saints University School of Medicine, said the power and phone lines were down, but that so far, there had been no reports of injuries among people associated with the school.

On St. Martin, the American University of the Caribbean suffered only minor damage from Hurricane Irma, Dr. Heidi Chumley, the executive dean, said Tuesday.

She said that the university hoped to continue the semester later this month at a temporary location in Britain.

Students who were evacuated from the island last week were shocked by the severity of the storm and felt lucky to get away.

Daniel-Mario Larco, 25, had left his off-campus apartment to take shelter on campus, and went to sleep in a classroom with fellow students. He was awakened in the early morning and told to go to the auditorium. Through the small windows, he said, “all you could see was a white sheet of water.”

They were there for more than six hours, Mr. Larco said.

The rest of the island, he knew, had it much worse. On campus, running water was soon restored, and the kitchen was working. But when he ventured out to return to his apartment, he found it flattened.

He gathered a few items of clothing he saw scattered on the ground and headed back to campus. A military plane flew the students to Puerto Rico.

It was not the first time that the United States government has had to evacuate Americans from a Caribbean medical school.

In 1983, the Reagan administration led an invasion of the island of Grenada, and evacuated students from St. George’s medical school, after a military coup ousted government leaders.

Grenada has not received the brunt of this year’s hurricanes but Charles Modica, St. George’s chancellor, said that when Hurricane Ivan hit in 2004, the school relocated to an osteopathic medical college in New York, among other places, and that students were able to complete the semester.

But on Tuesday, many families of Ross students were left in limbo.

“I have not slept, and cry frequently,” Robin Doyle, of Hanover, Minn., said in a text message to a reporter. Her son Jesse is in his final semester at Ross.

Lillianna Tisheh of Port St. Lucie, Fla., last spoke to her daughter, Leilah, 24, at 5 p.m. on Monday.

“The wind was hitting really really fast so they were staying in the little hallway in the apartment,” she said. “I called her back and didn’t get anything.”

At 7:37 p.m., her daughter sent a text message to her parents saying the electricity was gone and she was using the university’s Wi-Fi.

“Don’t worry,” it read. “I’ll be safe.”

Susan C. Beachy contributed research.

A version of this article appears in print on , on Page A10 of the New York edition with the headline: For Many Medical Students, the Caribbean Was Warm and Welcoming. Until Now.. Order Reprints | Today’s Paper | Subscribe